The 47-year-old former model officially ended her six-year-old marriage to the surviving member of The Beatles in 2008, reported Aceshowbiz.
"When I go down the street, I get kids coming up to me - half of them don't even know who he is," Mills said during her appearance on Ireland's "The Late Late Show with Ryan Tubridy".
"That's why he's got to do songs with Rihanna and Kanye West, so people remember (who he is)."
McCartney has collaborated with West, 37, on "Only One" and "All Day" that will be featured on the rapper's own full-length "So Help Me God".